Allergy refers to an exaggerated reaction by our immune system in response to certain foreign substances, i.e. bacteria, pollens, or dust, which are known as “allergen”. These allergens are sometimes seen by the body as harmful and dangerous, and one part of immune system is turned on, while in reality they were not infectious or toxic. When an allergen comes in contact with the body and create an allergic reaction, histamine and prostaglandin may be released subsequently and generate allergic disorder including airway inflammation, atopic dermatitis, allergic conjuctivitis, urticaria, eczema, specific gastrointestinal disorders or asthma.
It is reported that children in developed countries are prone to having allergy because of improved public health and the use of vaccine and antibiotics decrease the incidences of infections which normally against allergy or asthma. In medicine, it is called “hygiene hypothesis” stated that a lack of early childhood exposure to infectious agents leads to Th-2 mediated immune response, i.e. the overproduction of IL-4, IL-5 and IL-13. These Th-2 cytokines attract eosinophils, basophils and mast cell to the inflammation site along or cooperatively working with IgE and allergy occurs. On the other hand, IL-4 and IL-13 stimulate B cells' isotype switching to increase the blood level of IgE. According to the hygiene hypothesis, upregulation of Th-1 response, i.e. stimulating the expression of IFN-γ, might be effective in inhibiting allergic activities.
Many searches show that Lactobacillus sp. have immunoregulating activities in vivo, including stimulating the expression of cytokines, activating macrophages and natural killer cells, and production of antibodies (Madsen et al., 2001, Gastroenterology 121:580-591). Collins et al. (U.S. Pat. No. 7,390,519) disclosed that Lactobacillus salivarius strains AH102, AH103, AH105, AH109 or AH110 are useful in the prophylaxis and/or treatment of inflammatory activity as anti-inflammatory biotherapeutic agents. Hsu et al. (U.S. Pat. No. 6,994,848) discloses that a Lactobacillus paracasei strain, GM-080, stimulates IFN-γ secretion and treating allergy related diseases.
However, the effects of lactic acid bacteria isolated from various natural sources have not been thoroughly researched and fully discovered. The present invention provides a composition containing such a novel strain of Lactobacillus paracasei and its use for immunoregulating activities, which are different from related prior art strains, are disclosed.